/*
 *   Copyright 2021 zzh
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */

package com.aduib.boot.common.SPI;

import java.util.Comparator;

/** */
public class WrapperComparator implements Comparator<Object> {

  public static final Comparator<Object> COMPARATOR = new WrapperComparator();

  @Override
  public int compare(Object o1, Object o2) {
    if (o1 == null && o2 == null) {
      return 0;
    }
    if (o1 == null) {
      return -1;
    }
    if (o2 == null) {
      return 1;
    }
    if (o1.equals(o2)) {
      return 0;
    }

    Class clazz1 = (Class) o1;
    Class clazz2 = (Class) o2;

    OrderInfo a1 = parseOrder(clazz1);
    OrderInfo a2 = parseOrder(clazz2);

    int n1 = a1.order;
    int n2 = a2.order;
    // never return 0 even if n1 equals n2, otherwise, o1 and o2 will override each other in
    // collection like HashSet
    return n1 > n2 ? 1 : -1;
  }

  private OrderInfo parseOrder(Class<?> clazz) {
    OrderInfo info = new OrderInfo();
    return info;
  }

  private static class OrderInfo {
    private int order;
  }
}
